When free time runs out, demurrage covers a container that exceeds it at the marine terminal, while detention covers extended use of the equipment outside the terminal; the two are distinct charges, though they may arrive merged as a single line on a carrier's import invoice. Allowances are not standardized: they differ by carrier, port, direction, equipment type, and contract, so the desk works backward from each shipment's own expiry date, clearing customs, booking the truck, and pulling the box before the clock turns into money. When an invoice does arrive, the move is reconciliation before payment: the desk checks the charge against actual discharge and availability events before paying or disputing it. Container demurrage is also not the demurrage of vessel chartering, the sum a charterer owes when loading or discharging a ship exceeds the laytime agreed under a charter party.
Glossary
Demurrage
The charge that accrues when a container exceeds its free time at the marine terminal.